Boring and turning bar and bar-holder.



0. A. PALMGREN.

BORING AND TURNING BAR AND BAR HOLDER.

APPLICATION FILED M1014, 1910.

1,014,412. Patented Jan. 9, 1 912.

16 v 2 Ff7 1 UNITED STATES PATENT OFFICE.

CHARLES A. PALMGREN,

To all whom it may concern:

Be it known that I, CHARLES A. PALM- GREN, a resident of Chicago, in thecounty of Cook and State of Illinois, have invented a new and usefulImprovement in Boring and Turning Bars and Bar-Holders, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, forming part of this specification, inwhich Figure 1 is a view showing an end elevation of an attachmentembodying my invention applied to a lathe; Fig. 2 is a. side elevationof the attachment; Fig. 3 is a plan view of the same partly in section;and Fig. 4 1s a section on the line IVIV of Fig. 3; Fig. 5 is a detailview similar to the left hand end of Fig. 3, showing the sleeve reversedto secure a tool at right angles to the boring bar.

My invention is designed to provide a boring bar and holder of improvedcharacter which can be readily attached to lathes; which can be readilyand quickly adjusted; which can be used with tools of varying forms; andwhich can be attached to lathes in such a manner as to insure greatfirmness and rigidity.

A further object of my invent-ion is to provide a boring bar of thischaracter which can be used to equal advantage for turning; which can bemade in any desired size to suit different sizes of lathe on the market;

and which will permit the tools to be readily changed to make either anoutside or an inside cut.

In the accompanying drawings, the numeral 2 designates a lathe bedhaving therein the usual guide 3, on which is mounted the slide rest 4,having the usual feed devices 5. The slide rest is provided in its upperface with a T-groove 6, by means of which my improved attachment issecured thereto.

7 designates the bar holder which is of segmental form with a concaveupper edge 8 and a convex lower edge 9, the latter having a concavebearing in the upper face of a block 10, which is seated on the sliderest 4. The holder is secured to the slide rest, preferably by means oftwo bolts 11, having two different size heads at their lower ends whichengage the T-slot 6, which may be of two sizes, of the slide rest, andwhich extend upwardly through the block 10, and through the holder 7,being secured by nuts 12 at their upper ends wit-h convex face washers13 interposed between the nuts Specification of letters Patent.

OF CHICAGO, ILLINOIS.

BORING AND TURNING BAR AND BAR-HOLDER.

Patented J an. 9, 1912.

Application filed December 24, 1910. Serial- No. 599,141.

and the concave upper edge 8 of the holder. The holes in the holder forthese bolts are slotted, as shown at 11, in order to permit of thenecessary range of adjustment of the holder. The forward end portion ofthe holder is formed with a split sleeve portion 14, having clampinglugs 15, and tightening screws 16. The sleeve portion being locatedapproximately central of the edge portions 8 and 9.

17 is the sleeve of the boring bar, which is adjustably secured in thesleeve portion of the holder by means of the clamping lugs 15, andscrews 16, and which is open at, both ends and slotted at both ends forthe reception of the cutting tool.

18 is a bar extending longitudinally through the sleeve and which isprevented from rotating therein by means of a swivel clamping jaw at itsfront end. The front or cutting end portion of the sleeve 17 is slottedback from its forward end at opposite sides, as shown at 20, the rearwalls of these slots being inclined or beveled, as indicated at 21, toform clamping seats for the tool 22. The forward end portion of the bar18 also has a slot 23, extending diametrically therethrough to receivethe tool 22 and also the clamping jaw 24. This clamping jaw has a convexface 25 and also has a straight clamping face 26, to clamp the tool.-The jaw 24 is loosely seated in the slot of the bar 18 by means of thetransverse pin 27. The rear end portion ofthe bar 18 projects beyond theend of the sleeve 17, and is threaded to receive anut 28 having a leverhandle extension 29.

The clamping jaw arrangement 24 prevents rotation of the bar 18, wherebywhen the nut 28 is screwed up and is turned by means of the leverhandle, the bar 18 will be moved endwise to either clamp or release thetool, the tool being clamped between the face 26 of the jaw 24 and theinclined walls 21 of the slot 20. I I

Vertical adjustment of the bar may be quickly and rapidly effected byslacking the nuts 12. The attachment during this adjustment is at alltimes parallel to the bed of the lathe, thereby doing away with anytilting movement and insuring at all times a perfect and true cuttingbore, without readjusting the tool in the holder. By means of the twobolts 11, the attachment is securely held to the lathe with greatfirmness and rigidity, being much superior in this respect to securingthe bar in a tool post. The construction enables the operator to atanytime make quick changes. It will be further noted that there are noscrew clamps which can be tightened by the cutting actlon of the tool,thereby making it difficult to remove the tool. Itwill also be notedthat the bar is equally adapted for use either in borin or turning; theball joint connection 0 the holder provides means for insuring rapid andaccurate inside work; any suitable piece of steel can be'u'sed as acutting tool without special blacksmith or machinework to fit it, otherthan the grinding of the proper cutting edge; the tool can be changedfrom an outside to an inside out by simply reversing it in the holder;and the holder will hold any boring tool either round, square orhexagonal. The bar holder may be made of any size required to suit theparticular lathe.

I preferably also.

ing substantially vertical walls '31. By these provisions, I enable thesleeve to be reversed end for end with respect to the rod, so that thetool may be held in a straight position, instead of inclined, as shownin Fig. 3, the tool in this case being clamped between the jaw 24: andthe straight walls 31 of the'slots 30. The'jaw 24 beingpivoted, isenabled to adjust itself to the surface of the tool and thus provide arigid and secure clamp.

It will ,be obvious that various changes rest by engagement with theconcaved face .my hand.

and also to hold it in different adjusted positions on said bearing, anda boring bar intermediate of said faces; substantially as described.

.2. The combination with a lathe slide rest, of a bearing piece seatedon the slide rovide the opposite end of the sleeve 17 with tool slots30, havrality of securing bolts engaging rest and passing upwardlythrough said rest and having a concaved bearing surface,

-a tool bar holder having aportion of segmental form provided withconcaved and convexed faces, the convexed face adjustably engaging saidbearing ,surface the slide piece and through. slots'in the holder, andhaving clampin means at their upper ends engaging the concaved face, anda sleeve at one end of the tool bar holder having its axis intermediateof the-concaved and convexed faces thereof; substantially as described.

3. A boring bar c0 prising a sleeve having slots at its end, a arxtending longitudinally through said slee e.and having a slotted endportion, a tol holding jaw pivoted thereto and within the slotted end.portion of the bar and extending into the slots of the sleeve, andmeans for effecting a longitudinal movement of the bar within the sleeveto clamp the tool between the jaw and the sleeve; substantially asdescribed.

4. The combination with a lathe slide rest, of a bearing piece seated onthe slide rest and having a concaved bearing surface, a tool bar holderhaving a portionof segmental form provided with concaved and convexedsurfaces, the convexed surface engaging said bearing surface, the radiusof a plusaid surfaces being such that the tool bar holder is within acircle which is coincident.

with said surfaces; substantially as de-.

scribed.

5 The combination with a lathe slide rest, of a bearing piece seating onthe rest and having a concaved bearing surface, a tool bar holder havinga portion of segmental form provided with a convexed surface, theconvexed surface on the tool bar holder engaging the concaved bearingsurface on thebearing face, the radii of said surfaces being such thatthe tool bar holder is within the circle which is coincident with saidsurfaces; substantially as described.

In testimony whereof, I have hereunto set 0. A. PALMGRE-N.

